The present invention relates to the recording head of an inkjet printer; and, more particularly, the invention relates to a inkjet head that is compatible for use with ink based on a pigment.
The inkjet printer that forms an image by jetting ink onto paper or an overhead transparency film (OHP sheet) is smaller than an electrophotographic printer, and so it is popularly used in offices, as well as in general households.
When ink is deposited on the surface of a plate (nozzle plate) that is equipped with a nozzle for jetting ink from the inkjet head according to the prior art, the direction of jetting is changed or the jetting volume is reduced, with the result that the inkjetted position tends to deviate or the image density tends to be reduced.
To solve these problems, the current inkjet printer has a mechanism for removing ink deposited on the nozzle plate by wiping the nozzle plate surface with a silicone rubber member or the like, and methods are employed for making the nozzle plate surface ink-repellent.
For making the nozzle plate surface ink-repellent, there is a method of providing the nozzle plate with a plated film containing fine particles of fluorine based resin (disclosed in Japanese Application Patent Laid-Open Publication Nos. Hei 5-193141, Hei 5-116327, Hei 6-246921, Hei 7-125220, Hei 9-286941 and Hei 2000-86948), a method of providing the nozzle plate with a plastic film containing fine particles of fluorine based resin (disclosed in Japanese Application Patent Laid-Open Publication No. Sho 63-122550), a method of providing the nozzle plate with a film composed of silicone material (disclosed in Japanese Application Patent Laid-Open Publication Nos. Hei 4-234663 and Hei 9-267478), a method for providing a fluorine based resin film (disclosed in Japanese Application Patent Laid-Open Publication Nos. Hei 2-153744, Hei 3-53942, Hei 5-330060, Hei 5-338180, Hei 6-55739, Hei 6-106727 and Hei 6-143587) or a method of providing the nozzle plate with a film composed of a silane compound containing a fluoroalkyl group (disclosed in Japanese Application Patent Laid-Open Publication No. Hei 7-125219).
Further, a method is proposed wherein a solution formed by dissolving or dispersing perfluoropolyether in a solvent having a specific chemical structure is coated on the nozzle plate surface of the inkjet printer recording head, whereby ink repellency is provided (W097/35919).
The Japanese Application Patent Laid-Open Publication No. Hei 10-29308 also proposes a technique by which an ink repellent layer formed of a compound comprising a perfluoropolyether chain and alkoxysilane residue is provided on the surface of the nozzle head of an inkjet printer. This Publication also includes a proposal for top-coating the perfluoropolyether on the ink repellent layer in order to further improve the ink repellency.